文档介绍：An Abrupt Climate Change Scenario and Its Implications for United States
National Security
October 2003
By Peter Schwartz and Doug Randall
Imagining the Unthinkable
The purpose of this report is to imagine the unthinkable – to push the boundaries of current
research on climate change so we may better understand the potential implications on
United States national security.
We have interviewed leading climate change scientists, conducted additional research, and
reviewed several iterations of the scenario with these experts. The scientists support this
project, but caution that the scenario depicted is extreme in two fundamental ways. First,
they suggest the occurrences we outline would most likely happen in a few regions, rather
than on globally. Second, they say the magnitude of the event may be considerably smaller.
We have created a climate change scenario that although not the most likely, is plausible,
and would challenge United States national security in ways that should be considered
immediately.
Executive Summary
There is substantial evidence to indicate that significant global warming will occur during the
21st century. Because changes have been gradual so far, and are projected to be similarly
gradual in the future, the effects of global warming have the potential to be manageable for
most nations. Recent research, however, suggests that there is a possibility that this gradual
global warming could lead to a relatively abrupt slowing of the ocean’s thermohaline
conveyor, which could lead to harsher winter weather conditions, sharply reduced soil
moisture, and more intense winds in certain regions that currently provide a significant
fraction of the world’s food production. With inadequate preparation, the result could be a
significant drop in the human carrying capacity of the Earth’s environment.
The research suggests that once temperature rises above some threshold, adverse weather
conditions could devel